Kinematic error modeling & identification of EMA lifting servo mechanism

DOI:	10.11809/bqzbgcxb2024.08.014
Keywords:	EMA lifting mechanism; error source; error modeling; error separation; error identification; nonlinear least squares
Abstract:	Aiming at the problem that the kinematics model accuracy of EMA(Electromechanical Actuator) lifting servo mechanism is not high in large length diameter ratio, large inertia, and large mass weapon station, this paper uses the error separation identification method to model the kinematics model of EMA lifting servo mechanism with high accuracy. Based on clarifying that the kinematic error sources are zero position, geometry, clearance, and trend errors, combined with the closed loop vector method and hysteresis model, the theoretical kinematic model including all errors is established, and the different characteristics of each error are qualitatively summarized. Through the proposed static and dynamic error separation process based on error decoupling, the gap, zero position, geometric, and trend errors are effectively separated. The gap, zero position, geometric, and trend errors are effectively identified by using the double sensor method, nonlinear least square method, Fourier series method, and wavelet transform method respectively, and the influence degree of each error is quantitatively analyzed. The experimental results show that the decoupled nonlinear least squares method based on search interval can effectively separate the reproduction error (geometric error), and it is clear that the geometric error is the largest error source. The identified static error is substituted into the kinematic model. On the experimental platform, the accuracy of the kinematic model of the platform is improved by 96.6%. The error separation and identification method have theoretical reference values for the high precision kinematic modeling of the EMA lifting servo mechanism.
Issue:	Vol. 45 No. 8 (2024)
Published:	2024-09-02
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